Sealing mechanism



July 3, 1962 B. H. ROWE 3,04

SEALING MECHANISM Filed Dec. 12. 1960 EEI El I INVENTOR- El 3 59/4 20m?JIIJRNEY- United States Patent O 3,042,364 SEALING MECHANISM Brian H.Rowe, Cincinnati, Ohio, assignor to General Electric Company, acorporation of New York Filed Dec. 12, 1960, Ser. No. 75,250 8 Claims.(Cl. 253-39) This invention rel-ates to a sealing mechanism and, moreparticularly, to a sealing mechanism forming part of a tip turbine fansuch as may be used in a VTO type powerplant.

In present day VTO-vertical take-off-aircraft, one of the generalarrangements receiving favorable consideration is the fan-in-wing orfan-infuselage type wherein a large fan or fans may be verticallymounted in a frame, be it fuselage or wing, for the movement of largequantities of air therethrough to obtain vertical lift. The fan isusually driven by a gas generator which supplies its products ofcombustion to an annular scroll surrounding the fan which, in turn,directs the exhaust gases through a nozzle to turbine buckets mounted onthe ends of the fan and the exhaust and air are directed downwardly toproduce lift.

In such arrangements, it becomes important to provide sealing meansbetween the scroll and the supporting frame members. Under the action ofthe exhaust gas the scroll can expand in three planes, i.e. radially,vertically, and tangentially. The supporting frame members, being out ofthe exhaust gas stream, are relatively cold compared to the scroll sincethey are generally subjected to ambient temperature conditions. Inaddition, the frame members form part of the wing structure or fuselagestructure and it is important that the hot exhaust does not come incontact with these portions of the aircraft where it would seriouslydamage them. In addition, it is important that the exhaust gases beconfined to their passage through the turbine blades so that all energymay be extracted from the gases. Obviously, leakage of cold gas or airinto the exhaust stream by suction from the space between the framemembers and the scroll would lower the efiiciency of the turbine.Conversely, loss of the exhaust gas to the space between the framemembers and scroll would result in a loss of pressure in the exhaust gaswhich is part of the energy extracted by the turbine.

Accordingly, it is the main object of the present invention to provide anovel sealing mechanism for such an application which prevents this lossof efiiciency and adequately seals between the scroll and frame members.

A further object is to provide such a sealing mechanism which iscomposed of light weight parts and has a high sealing efficiency.

Another object is to provide such a sealing mechanism which is extremelyflexible to provide positive sealing under movements of the scroll inthree planes and still maintain the seals in a substantially commonplane relation.

Briefly stated, the invention provides a sealing mechanism between thescroll and frame members which comprises contiguous flanges on each sideof the scroll extending toward the frames. Each flange has a hinge orbead on its outer edge to provide a pivot for a mating member. Themating member is formed of a pair of plates, each plate having anenlarged portion to grasp the bead and extending in a tongue ormale-like extension toward the frame member. Each plate of the pair ofplates is axially offset from the other. A series of such plates nestwithin one another to form a continuous smooth tongue. Opposing thetongue and secured to the frame members is a second set of plates toform a female member extending toward and grasping the tongue in asealing relation. Again, the female member is made of a series of3,42,364 Patented July 3, 1%62 ice tangentially or axially offset platesin nesting arrangement to provide a smooth continuous seal with thetongue member. On the ends of the scroll similar sealing means areprovided wherein the female member is a continuation of the side femalemembers and the male or tongue member overlaps the side male or tonguemembers. Further, the seals are arranged in a substantially common planewhich, with the pivotal arrangement of the male member and the freedomof movement within the female member, reduces stresses and strains onthe parts while forming an effective seal.

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter which I regard as myinvention, it is believed the invention will be better understood fromthe following description taken in connection with the accompanyingdrawing in which:

FIGURE 1 is a partial plan view illustrating the scroll and framemembers in relation to the fan;

FIGURE 2 is a partial cross-sectional View on line 2-2 of FIGURE 1showing the relation of the members;

FIGURE 3 is an exploded partial perspective view showing the individualparts of the seal and their offset relation;

FIGURE 4 is a partial plan view illustrating the scroll nozzle andshowing the overlapping arrangement of the seal; and

FIGURE 5 is a cross-sectional view of a modification of one of thesealing members.

Referring first to FIGURE 1, there is shown a typical arrangement usedto provide exhaust gases to a tip turbine fan. The gases are received,from a suitable gas generator by suitable means not shown, by a scroll15 which may be annular in shape and cross-section. The scroll may be apartial scroll for partial admission thus appearing as a U-shaped memberin plan as shown in FIGURE 1. The scroll is supported, in a manner notforming part of this invention, at a fixed point 11 and suitablesupporting points along the scroll to permit expansion. The dottedportion 12 illustrates how the scroll can expand radially andtangentially under operation. In addition, it may expand in the verticaldirection as well. The whole VTO powerplant is supported in forward andrear continuous frame members 13 and 14 respectively by means not shown.

In order to drive the lift fan 15, the scroll exhausts through acontinuous nozzle 16 as seen in FIGURE 2. The fan 15 is driven byturbine buckets 17 mounted on the periphery of the fan 15 inconventional manner. It can also be seen in FIGURE 2 that the verticalmovement of the scroll referred to above, is vertical movement in theplane of the drawing.

As thus far explained, it will be seen from FIGURE 2, that exhaust gasexpelled from the scroll Ill through nozzles 16 drives turbine buckets17 which, in turn, power the fan 15 to provide for vertical movement ofair therethrough. It can also be seen that scroll .10 as shown in FIGURE2 is moving under the heat of expansion in all directions whereas fiamemembers 13 and 14 out of the path of the exhaust gases are relativelystationary. It is extremely important that no leakage take place betweenthe frame members and the scroll. Leakage of ambient air between framemembers 13 or 14 and scroll 10 into the space between buckets 17 andnozzle 16 seriously lowers the efliciency of the turbine resulting in aloss of energy to the turbine. This leakage may come about by reason ofthe suction action due to the exhaust of the gases downwardly throughscroll 10 and buckets 17, which tends to draw in air fram the spacebetween the scroll and the frame members. At diiferent times duringoperation of the powerplant, the pressure in the vicinity of buckets 17may be higher than ambient which can result in a leakage of gas outthrough the aforementioned spaces, again resulting in a los ofefficiency due to loss of pressure.

In order to seal the above mentioned spaces effectively and to allow forthe almost universal movement of the scroll, it has been necessary toprovide a seal which functions cooperatively with its adjacent membersand lends itself effectively to this particular combination orpowerplant arrangement.

Since the seals, generally indicated at 18 on each side of the scrollare identical, except for size, it will be necessary to describe onlyone of the seals in detail.

Referring now to FIGURE 3, in order to mount one of the sealing members,a continuous flange 19 is connected to the scroll .10 and is contiguoutherewith throughout its length. The flange 19 thus projects from theside of the scroll toward the frame member 14. For purposes of hinging,flange 19 is provided along its outer edge with bead portion 20 that islarger in diameter than the thickness of flange 19.

Cooperating with the bead portion, there is provided a first pair offiat plates 21, 22, which plates may be light weight sheet metal, andwhich are axially offset from one another in a tangential direction asseen in FIGURE 3 for a purpose to be described. These plates are securedtogether by any suitable means such as welding and have formed innerportions 23 grasping the bead 20 lengthwise of the plates to provide apivotal connection therewith. Thus, the portion 24 forms a flat tongueor male member extending toward frame member 14.

Cooperating with the aforementioned seal member on the scroll '10, is asecond pair of U-shaped axially offset plates 25, 26 mounted on theframe member 14 by any suitable means 27. These plates are formed in aU-shape, as may be seen in FIGURE 3, and cooperate with a secondcorresponding symmetrical pair of axially otfset plates 28, 29 whichabut with plates 25, 26; all the plates being biased together to form anopening therebetween lengthwise of the plates and directed forward thetongue 24 of the adjacent sealing member. As can be seen in FIGURE 3,the two sealing members are designed to fit together so that the femalemember on frame 14 firmly grasps tongue 24 within opening 30 in acontinuous seal. By the phantom arrangement shown it can be seen thatthe sealing members are made up of segments which nest within oneanother due to the offset arrangement of the individual plates. Thus,there is no broken surface presented by the sealing members along thesealing surfaces. Further, as can be seen in FIGURE 3, the jointsbetween the segments of the sealing members in both cases are offsetfrom each other so that the joints do not overlap when the member aretogether, but each joint falls on the smooth unroken surface of theopposite member.

It will be appreciated that the term U-shaped has been used to describeplates 25, 26 and 28, 29 whereas only one set of these plates, such as25, 26 need have an actual U-shape. Thus, the term U-shape is intendedto include such obvious equivalents. By the use of the U-shape plates25, 26 and 28, 29 it can be seen that a tube-like structure parallel tothe tongue 24 is provided on frame member 14 to cooperate therewith aspreviously described.

Referring to FIGURE 5, a cross-sectional view of the modification justmentioned is shown wherein the female member of the seal is formed byU-shaped plates 25 and 26 and substantially flat plates 28 and 29 toform the tube-like member as described above. Therefore, the use of theterm U-shaped plates as used in the specification and claims, isintended to connote the tubelike formation of the female member ratherthan the specific shape of the individual plates themselves.

With the description of the individual seal members as shown in FIGURE3, the assembly of such members can be seen by reference to FIGURE 4,which is a partial plan view of the sealing structure in the plane ofFIGURE 1, showing the overlapping sealing members as applied to the rearframe 14. In this figure, scroll 10 has its pivotally attached fiatplates 22, 24 overlapping as shown. These form the tongue extendingtowards frame member 14 lengthwise of the scroll. These mesh or engagein sealing relation with the mating or female sealing member comprisingplates 25, 26 and 28, 29. In this figure it can be clearly seen how thejoints 31 of the tongue plates are axially offset from the joints 32 ofthe matching sealing plate members to provide a smooth sealing surfacebetween the sealing members. It can also be seen how the ends of thetongue members 24 overlap at the end of the scroll at 33 whereas thereceiving or female seal 25 forms a continuation of the side tube-likestructure shown in FIG- URES 3 and 5.

Referring again to FIGURE 2, it can be seen that the seals all lie on acommon plane 34 to reduce stresses and this is true even underexpansion, i.e. the substantially common plane low stress relationship.

Thus, the seal of the present invention is formed by part of thesurrounding structure in the specific embodiment illustrated and claimedand it can be seen that an effective seal is formed between the scrolland frame structure to prevent the leakage of fluid either way.

While I have hereinbefore described a preferred form of my invention,obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifical- 1y described.

I claim:

1. Sealing mechanism for a tip turbine fan powerplant comprising, anannular scroll for the passage of exhaust gases and subject to movementin three planes, frame members out of the path of the exhaust gases oneach side of the scroll and contiguous therewith, a flange projectingfrom said scroll on each side lengthwise thereof generally toward saidframe members and having a head on the edge thereof, first plate meansforming a tongue pivotally connected to said flange at said bead andextending toward said frame member, second plate means secured to saidframe to form a female member extending toward and grasping said tonguein a sealing relation, said plate means lying in substantially a commonplane to form a seal between said scroll and frame member.

2. Sealing mechanism for a tip turbine fan powerplant comprising, anannular scroll for the passage of exhaust gases and subject to movementin three planes, frame members out of the path of the exhaust gases oneach side of the scroll and contiguous therewith, a flange projectingfrom said scroll lengthwise thereof on each side of said scrollextending toward said frame members and having a bead on the edgethereof, first plate means forming a tongue pivotally connected to eachflange at said head and extending toward each frame member, second platemeans secured to each frame to form a female member extending toward andgrasping its mating tongue in a sealing relation, said plate means lyingin substantially a common plane to form seals between said scroll andframe members.

3. Sealing mechanism for a tip turbine fan powerplant comprising, anannular scroll for the passage of hot exhaust gases and subject tomovement in three planes, frame members out of the path of the exhaustgases on each side of the scroll and contiguous therewith, a flangeprojecting from each side of said scroll lengthwise thereof generallytoward one of said frame members, an enlarged head portion extending thelength of said flange on the edge thereof, a first pair of platessecured together and axially olfset from one another, said plates havingformed inner portions grasping said bead for pivotal movement thereon, asecond pair of U-shaped axially offset plates secured to said framemember with corresponding symmetrical plates abutting to form atube-like structure, said second and corresponding plates being biasedtogether and having an opening lengthwise thereof toward and clampingsaid first plates, all said plates lying in substantially a common planeto form a seal between said scroll and frame member.

4. Sealing mechanism for a tip turbine fan powerplant comprising, anannular scroll for the passage of hot eX- haust gases and subject tomovement in three planes, stationary frame members out of the path ofthe exhaust gases on each side of the scroll and contiguous therewith, acontinuous flange projecting from each side of said scroll lengthwisethereof generally toward said frame members, an enlarged bead portionextending the length of each flange on the edge thereof, a first pair offlat plates secured together and axially offset from one another, saidplates having formed inner portions grasping said bead lengthwise of theplates for pivotal movement thereon, the outer portion forming a fiattongue extending away from each side of said scroll, a second pair ofU-shaped axially offset plates mounted on each frame member withcorresponding symmetrical plates abutting to form a tube like structureparallel to said tongue, said second and corresponding plates beingbiased together and having an opening lengthwise thereof toward andclamping said tongue, all said plates lying in substantially a commonplane to form a seal between said. scroll and frame members.

5. Apparatus as described in claim 4 wherein a plurality of pairs ofplates extend the full length of said scroll, each said pairs of platesresting in the offset portion of the adjacent pair to form a continuousjointed and segmented sealing member.

6. Apparatus as described in claim 5 wherein the segmented sealingmember by its nesting arrangement provides a continuous smooth sealclamping surface on said tongue.

7. Apparatus as described in claim 6 wherein the joints between thesegments of said tongue are offset from the joints between the segmentsof said second pair of plates.

8. Apparatus as described in claim 7 wherein the scroll is generallyU-shaped in plan and like plate sealing members are provided at the endsof said scroll, said end tongue overlapping said side tongues and saidend tubelike structure forming a continuation of said side tube-likestructure.

References Cited in the file of this patent UNITED STATES PATENTS1,082,886 Ljungstrom Dec. 30, 1913 1,313,648 Steenstrup Aug. 19, 19191,740,800 Wiberg Dec. 24, 1929 2,584,899 McLeod Feb. 5, 1952 2,772,069Hockert et al Nov. 27, 1956 2,799,473 Smith et a1. July 16, 1957

